Molybdenum

Molybdenum takes its name from Ancient Greek "molybdos", meaning lead, because its ores were originally confused with lead ores.

Molybdenum does not occur naturally as a free metal on Earth, but instead in various oxidation states in minerals. The free element, which is a silvery metal with a grey cast, has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and therefore finds most of world production of the element (about 80%) is in making many types of steel alloys, including high strength alloys and superalloys. Industrially, molybdenum compounds (approx. 14% of world production of the element) are used in high-pressure and high-temperature applications, such as pigments and catalysts.

The production of pure molybdenum metal involves the molybdenite ore being first heated to a temperature of 700 °C and the sulfide is oxidized into molybdenum(VI) oxide by air. The oxidized ore is then either heated to 1,100 °C (2,010 °F) to sublimate the oxide, or leached with ammonia, which reacts with the molybdenum(VI) oxide to form water-soluble molybdates. Copper, an impurity in molybdenite, is less soluble in ammonia. To completely remove it from the solution, it is precipitated with hydrogen sulfide.

Pure molybdenum is produced by reduction of the oxide with hydrogen, while the molybdenum for steel production is reduced by the aluminothermic reaction with addition of iron to produce ferromolybdenum. A common form of ferromolybdenum contains 60% molybdenum.

Avon Specialty Metals trades the following forms of molybdenum -

  • Vacuum grade - pure fully sintered plate/bar/rod/pellets
  • Airmelt grade - sheet, plate, wire, overspray, condensates etc.
  • Sputtering target scrap - pure and alloyed (MoTi, MoTa)
Moly

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